Write the expanded form of 0.0504.

Place value of decimal digits after decimal point towards right is: $\frac{1}{10}$, $\frac{1}{100}$, $\frac{1}{1000}$, $\frac{1}{10000}$...

To get the expanded form of decimal, each digit has to be multiplied with its place value.

$\therefore$ Expanded form of $0.0504=\frac{0}{10}+\frac{5}{100}+\frac{0}{1000}+\frac{4}{10000}=\frac{5}{100}+\frac{4}{10000}$